Fluid-pressure brake apparatus.



zeA

- WALTER V. TURNER, F WILKINSBURG, PENNSYLVANIA, SSIGNOR TO THE WESTING- y eerie.

HGUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORIIPORATION QF 'PENNSYLVANI.

FLUID-PRESSURE BRAKE IAll??ARSIWJS.v

imanes.,

Specification of Letters Patent. Paul-,rented Aug.' 27, 1918.

Application led November 29, 1916. Serial No. 1311,981.

Anew and useful Improvements in Fluid- PressurevBrake Apparatus, of which the following is a specification.

This invention relates to fluid pressure brakes, and more particularly to a brake equipment employing an auxiliary reservoir of small volume.

Where a small auxiliary reservoir volume is employed, it is sometimes diiiicult toobtain a suliicient dierential pressure on the auxiliary reservoir side 'of the triple valve piston when a light reduction in brake pipe pressure is made, toelect the movement of the triple valve piston to application position, by reason of the triple valve piston displacement-tending to increase the auxiliary reservoir volume and thus reducing the auX- iliaryv reservoir pressure and on account of leakage from the auxiliary reservoir past the triple valve piston to the brake pipe.

The principal object-of my invention is toovercome the above diiculty by providing an enlarged auxiliary reservoir volume to insure the movement of the triple valve piston to application positionand then i'e-V ducing the auxiliary reservoir volume to normal upon applying the-brakes. l

In the accompanying drawing, the single figure is a diagrammatic view, partlyin section, oliZ a fluid pressurev brake apparatus, showing my improvement applied thereto. As'shcwn in the drawing, a triple valve device 1l of the usualv construction may be provided, and connected to the triple valve device by a pipe 2, is an auxiliary reservoir 3 of small volume.

- The triple valve device 1 controls the admission and release of fluid under pressure to and from a brake cylinder 4 through a pipe 5 in the usual manner. l

According to a preferred form of myinvention, a modified non-pressure head 6 is applied to the brake cylinder 4 and ispro- 'vided with a. valve seat for a slide valve 7 contained in a valve chamber 8, and adapted to control a passage 9 leading from pipe 10 and connected with auxiliary reservoir pipe 2, to said chamber.

- The valve chamber 8 is connected by a.

pipe 11 with a normally charged supple- `mental reservoir 12 and the slide valve 7 is" adapted to be actuated by the movement of4 brake cylinder piston rod 13 which is connected to the usual brake cylinder piston 14.

For this purpose, a pivoted lever 15 is provided, which is adapted to engage at one end; with apin 16 carried b, the valve 7, andv having the other end o the lever arranged to engage within a slot 17 Provided in the piston rod 13.

When the brake cylinder piston 14 is in normal release position, the lever yl5 holds the valve 7 inn position uncovering passage 9, so that the auxiliary reservoir 3 is connected to the supplemental reservoir 12, and consequently, upon reducing the brake pipe pressure to eii'ect an application of the .I

brakes, the ecctive .volume of the auxiliary plemental reservoir 12. By thus providing a large auxiliary reservoir volume, any leakage past the triple valve pistonA will have little'eii'ect in reducing the auxiliary reservoir pressure, so that movement of the triple valve piston to application position as-,

sure'd.

Upon movement of the triple valve de viceto service application position, fluid is supplied in the usual manner from the auxil ka small auxiliary reseryoir is retained,l vhile Vreservoir will include the volumc of the sup the diiculties by reason Iof'lealrage around the triple valve .are obviated.

- Upon releasing lthelbrakes, the ymovement of the brake cylinder piston rod 13 causes the lug 18 thereon to enga-ge the lever 15 and shift same so as to move the valve 7 and again open the passage 9. y

Having now described my invention, what I claim as new and desire to secure by Letters Patent is 1. ln a fluid pressure brake, the combination with an auxiliary reservoir, of an addi- 

